The present invention relates to minimally invasive surgical systems and methods. It finds particular application in conjunction with image-guided needle biopsies performed using continuous computed tomography (CCT) scanning or other similar imaging systems, and will be described with particular reference thereto. However, it is to be appreciated that the invention is also applicable to other imaging modalities and other biopsy surgical techniques.
It is often desirable to sample or test a portion of tissue from human or animal subjects, particularly in the diagnosis and treatment of potentially cancerous tumors, pre-malignant conditions, and other diseases or disorders. Typically, in the case of tumors, when the physician suspects that cancer or an otherwise diseased condition exists, a biopsy is performed to determine if in fact cells from the tumor are cancerous or otherwise diseased. Many biopsies, such as percutaneous biopsies, are performed with a needle-like instrument used to collect the cells for analysis.
In recent years, the performance of needle biopsies has been enhanced by the use of x-ray and computed tomography (CT) scans. The imaging equipment allows an interventionalist, such as a radiologist, surgeon, physician, or other medical personnel, to track the insertion of interventional devices, such as biopsy needles, in a subject during diagnostic and therapeutic procedures. While such imaging modalities are helpful to the interventionalist and the patient, they have certain drawbacks.
For example, with such image-guided procedures, the tracking of needle position is not done in real-time. That is to say, a static image is obtained and the needle position noted therein. Subsequently, the needle is advanced or retracted by a small amount and another static image obtained to verify the new needle position. This sequence is repeated as many times as necessary to track the needle's progression. Such a procedure tends to be time consuming insomuch as the needle progresses by only a short distance or increment between imaging, and needle progression is halted during imaging. Moreover, accuracy suffers to the extent that in the interim, i.e., between images, the needle's position cannot be visualized.
With the development of CCT imaging and fluoroscopy, real-time imaging has been made possible. In CCT scanning, a rotating x-ray source irradiates the subject continuously, generating images at a rate of approximately six frames per second. The use of CCT or fluoroscopy by the interventionalist for real-time guidance and/or tracking of the needle during biopsies is gaining popularity. As a result, biopsies have become not only more accurate, but also shorter in duration.
However, a problem resides in protecting the interventionalist from radiation exposure. In needle biopsies, for example, often the biopsy needle and guide are held within or close to the plane of the x-ray radiation so that the needle-tip will reside in the image plane thereby permitting continuous tracking. Staying close to the plane of imaging also, more often than not, allows for the distance the needle passes through the subject to be minimized. Consequently, this typically results in the interventionalist placing his/her hands in the x-ray beam. The hands of an interventionalist who performs several such procedures per day can easily receive a toxic dose of radiation. Therefore, it is desirable to provide interventionalists with a way to perform needle biopsies using CCT scanning without the risk of radiation exposure.
One proposed approach involves the use of a mechanical system which allows the interventionalist to manipulate the biopsy needle while his hands remain clear of the x-ray beam. However, such systems with mechanical linkages reduce or eliminate the tactile sensations (e.g., force, shear, and/or moment on the needle) otherwise available to an interventionalist directly manipulating the needle. This is disadvantageous in that interventionalists typically obtain useful information regarding the procedure from these tactile sensations. For example, they are often able to feel the needle transition between different tissue types, contact with bones, etc. The interventionalist generally desire this "feel" as they perform biopsies. To trained personnel, it serves as an additional indication of the needle's location.
The present invention provides a new and improved system and technique for performing a needle biopsy that overcomes the above-referenced problem and others.